Figure 6. Dorsal view of the carapace for small juveniles of (a) Elseya
albagula (Queensland Museum [QM] 36044, carapace length [CL] 91.9 mm); (b) Elseya
lavarackorum (unreg.); (c) Elseya sp. [Johnstone]; (c) Elseya irwini (paratype
QM 59021, CL 103.6 mm); and (e) Elseya dentata (Australian Museum [AM] 45481, CL 120.5 mm).
Refer also to Fig. 1.
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Figure 7. Lateral view of the head of the female holotype of Elseya
albagula (Queensland Museum J81785, carapace length 382.4 mm). Note the prominent barbels,
prominent tomial sheath, prominent scales on the temporal region, and pupil indistinct from iris.
Multivariate Comparisons Species in the E. dentata generic group are conservative in body form, and this is reflected in the outcome of discriminant function analyses. For females, four ratio variables contributed significantly to discrimination among species (Fig. 8a): V2/V1 (R2 0.70, F 13.52, p < 0.0001), IO/HL (partial R2 0.44, F 4.34, p < 0.01), HW/CL (partial R2 0.47, F 4.38, p < 0.02), and IO/OD (partial R2 0.40, F 3.57, p < 0.05). Refer to Appendix A for details of measurements. Canonical variate 1 explained 47.8% and canonical variate 2 explained 45.7% of the variation among group centroids. For males, three ratio variables contributed significantly to discrimination among species (Fig. 8b): V2/CL (R2 0.82, F 44.96, p < 0.0001), OD/HL (partial R2 0.40, F 5.99, p < 0.005), and HW/CL (partial R2 0.30, F 3.78, p < 0.05). Canonical variate 1 explained 80.5%, and canonical variate 2 explained 19.4% of the variation among group centroids. Crossvalidation error rates in classification to species were 22.1% for females and 4.1% for males (Table 4). Hence, on the basis of the measurements included in this analysis, discrimination between E. albagula and the other species is not diagnostic (Table 4), reflecting the conservatism in overall body form among species in this group. |
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